Adjustable jar trip spring



June19, 1951 ER 2,557,238

ADJUSTABLE JAR TRIFSPRING I Filed March 22, 1948 I 2 Sheets-Sheet 1INVENTOR, 270M224 Zflcyjer;

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' ADJUSTABLE JAR TRIP SPRING Filed March 22, 1948 2 Sheets-Sheet 2 fly8.

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Patented June 19, 1951 ,UNITED STATES PATENT OFFICE 2 Claims.

This invention concerns apparatus used in the deep well industry and isan adjustable tension, tripping jar assembly attachable at a suitablelocation in the length of a tool or other well string.

Jar assemblies are used to strike sudden sharp jolts to lower sectionsof a tool string while in use in a well hole, and a purpose of theinstant invention is to provide a jar assembly in which the degree ofstring tension required before the hammer element can trip oif can bereadil regulated from the top of the tool string while the jar assemblyis in operational position deep in the hole.

It has long been the practice to regulate the tripping tension in jartools and an intent of this invention is to provide an improvement andsimplification of the tripping control means.

Further, the invention provides a tripping control in which theindividual parts are simple of manufacture and installation, and,particularly, are of sturd structure whereby to stand up for a longservice life notwithstanding the severe strains and attritional natureof the employment of the tool.

Especially, it is an object to provide a tool jar which is free ofdelicate elements and tricky modes of adjustment and release.

The invention resides in certain advancements in this art as set forthin the ensuing disclosure and having, with the above, additional objectsand advantages as hereinafter, developed, and whose constructions,combinations and sub-combinations and details of means and the manner ofoperation will be made manifest in the following description of theherewith illustrative embodiment; it being understood thatmodifications, variations, adaptations and equivalents may be resortedto within the scope, spirit and principles of the invention as it isclaimed hereinafter.

Figure 1 is an axial, sectional elevation, with the barrel locked inopen or stroke prepared position as to the inside mandrel.

Figure 2 is a cross-section on line 2-2 of Fig. 1.

Figure 3 is a cross-section on line 33, Fig. 1.

Figure 4 is a cross-section on line d4, Fig. 1.

Figure 5 is a cross-section on line 5-5, Fig. 1.

Figure. 6 is a side elevation of the mandrel with its affixed wash pipestem and the expander.

Figure '1 is a side elevation of the locking sleeve,

Figure 8 is an elevational section of the internally grooved shoe.

The jar assembly embodies a top sub 2 attachable to the near section ofa drilling or other tool string (not shown) and has a packing 3 on awash pipe or stem 4. A feature of this stem 2 is that it has externalthreads 4t later referred to again and constitutes a part of the meanswhereby the intensity of the hammer impact on a jar anvil is regulated.

The lower end of the stem 4 is securely threaded at 5t into and becomesa rigid part of a mandrel 5 having a bottom pin 6 to attach to a drillcollar or other work tool (not shown).

When the collar and its tool become frozen in a hole the attachedmandrel stands as an anchor therewith. The purpose of this invention isto loosen and pull as much of the attached lower tool as may bepossible.

Slidable along the lower end of the mandrel 5 is a bushing H fixed inand forming the hammer part of an elongate barrel 1 whose upper endscrews onto the sub 2. The barrel can be lowered or raised on themandrel by operation of the drill string when the jar is in assembly anduse therewith.

The main body of the mandrel slidably and turnably fits the barrel boreabove the bushing H and a torque drive rib 8 of the barrel is designedto shift down into one or another of lower keyways 50 formed in themandrel 5 for rotational drive of the mandrel (in either direction), andis adapted to move up, as the barrel is pulled, into slots 5s betweenlongitudinal lugs 5:1: rigid with the upper portion of the mandrel.

The lugs 5a: are spaced up from the channels 50 a distance slightly morethan the length of the drive rib 8 of the barrel to form acircumferential clearanceway on the mandrel 9 which permits the rib tobe rotated with the barrel about the upper end of the mandrel. Thiscapacity for rotation is availed of as later shown herein.

For the purpose of putting tension in the tool string and inv the frozenmandrel, as may be needed, and to use the stretched tool string as acontractile spring there is rigidly fixed in the barrel l a removable,tubular locking sleeve l0 whose bore is annularly grooved at llig tosolidly receive peripheral beads l lb provided on the central portion ofan elongate sleeve II. The sleeve II is longitudinally kerfed or splitat Illc to its top end to form spring fingers H) which constantlycontract toward, and slide on, a central, conic expander described laterherein. The unsplit, lower end of the sleeve H slidably fits on the stem4 below a stem shoulder 5b whose function is to engage a sleeve seat H sstop-upward shift of the sleeve at that limit as the barrel is beingpulled upward and lifts the sleeve from the top end face of the mandrelbody (to which position it can drop). A barrel liner Illa: holds the 3locking sleeve ID in position on a shoulder 15 of the barrel; said linerfitting the barrel bore wall in the barrel.

Fig. 1 shows the hammer bushing H spaced below the anvil face a of themandrel 5, and shows the sleeve ll interlocked at Hb with and as pulledby the locking sleeve [0, in the barrel, up against and stopped by theshoulder 51). As tension in the drilling string (in use of the jarassembly) is increased to pull the mandrel, eventually the lockingsleeve will compress the mandrel arrested spring sleeve fingers II andthe barrel organization will be free to snap up and bang the hammerbushing 1-1 against the anvil 5a of the mandrel 5.

The shock on the mandrel may loosen the attached stuck collar and itstool but if not then the barrel is lowered to effect re-engagement ofthe barrel locking sleeve on the sleeve beads ill) and a string tensionand jar function is repeated.

Means are provided in this assembly whereby the degree of trippingresistance of the spring sleeve can be increased or decreased at will byoperation of the drilling string while the jar assembly is still inworking position in the given fish hole. This means includes an elongateexpander tube l3 slidably fitting the mandrel stem 4 below and engagingthe mentioned threads it. A spline l4 fixed in the sub 2 slides in asplineway 13s in the expander tube, and when the barrel sub is rotatedthe spline rotates the expander tube and this is screwed at it up ordown on the stem i and inward or outward as to the contracted ends ofthe trip fingers of the sleeve. The finger engaged end of the stationaryexpander tube is conical and therefore the fingers are therebypositively expanded or are permitted to contract and thereby regulatethe resistance offered to the locking sleeve I l; according to direction of expander tube shift. Thus the blow by the hammer is controlled.

The expander tube can only be rotated 0n the pipe 4 when the rib 8 ofthe barrel is brought to the level plane of the clearanceway 9. At sucha register of the parts a rotation of the barrel will turn the spline Iand this will rotate the expander tube to expand or to contractivelyrelease the fingers of the spring sleeve H and therefore change theirreaction on the locking sleeve l0. Following such an adjustment of tripcontrol the barrel is again put under tension to efiect a new jarstroke. Repeated strokes and resetting of spring reaction can be madeuntil the fish comes loose, or the job has to be given up for lost.

The operation is as follows: Fig. 1 shows the hammer H spaced down fromthe anvil for a jar stroke, and the fingers I I f are in looking withthe grooves of the locking sleeve H]. Tension is now put on the barrelto a degree that will overcome the inbending resistance of the tubesupported fingers and at that moment the barrel becomes unlocked andinherently springs the hammer up against the stuck mandrel anvil.Greater tension may be built in the barrel if the fingers areadditionally expanded as desired by axial adjustment of the expandertube as above set out.

What is claimed is:

1. A well tool jar assembly comprising, in combination; a hammer barrelhaving a tubular hammer bushing mounted in its lower end and a tubeslidably mounted in its upper end, said tube having a conical lower end,an elongate stem mounted within said barrel and upon which said tube ismounted, an elongate spring sleeve slidable in the barrel and having anupwardly projecting set of resilient, contractile fingers whose tipsslidably engage said conical tube end and said spring sleeve beingslidable on said stem and the latter having an abutment shoulder locatedbelow said tube and serving to engage an internal flange in said springfinger sleeve to hold the spring finger sleeve in a given position onthe stem, a mandrel element slidably mounted in the lower end of saidbarrel and having a pin connection at its lower end and connected tosaid stem at its upper end, an anvil shoulder positioned on the lowerend of said mandrel element in opposed relationship to said hammerbushing, the upper end of said mandrel element having a set of splinesand a set of keyways therein spaced below the set of splines to form anannular clearanceway, a drive key fixedly mounted within the lower endof said barrel and engageable in lowered position within said keyways onsaid mandrel element and turnable on the mandrel element in theclearanceway, and trip release means for releasably connecting themandrel element to the barrel including a looking sleeve fixedly mountedwithin said barrel having a series of internal grooves therein, saidspring sleeve having annular bead members externally thereof and adaptedto be engaged in the grooves of said locking sleeve, whereby saidabutment shoulder and internal flange serve to prevent upward movementof said spring sleeve when upward pull is applied to said barrel andupon reaching a predetermined tensile force the beads on the springsleeves are released from the grooves of said locking sleeve to allowsudden relative movement of the barrel and the mandrel element to impactsaid hammer bushing upon said anvil shoulder.

2. The assembly of claim 1; the said tube bein threaded on said stem andsplined to the barrel so that rotation of the barrel and said key, inthe clearanceway, on the mandrel element will axially shift the tube andthereby vary the tensile force required to overcome the spring force ofthe contractile fingers according to the relative position of theconical tube end.

DGNALD U. SHAFFER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,885,043 Beck Oct. 25, 19321,954,513 Beck Apr. 10, 1934 1,989,907 Beck Feb. 5, 1935 2,013,127 BowenSept. 3, 1935 2,158,406 Collett et a1 May 16, 1939 2,309,866 Reed Feb.2, 1943

